As illustrated by the prior art arrangements, the hand is most often protected against trauma and contusion by a padded device; those who use percussive hand tools (such as a hammer or axe) or who participate in sports (such golf, the racquet sports or baseball in particular) are commonly appreciative of the protection afforded by such shields. Indeed, a single contusion to a hand bone of a baseball player will often create an area of tiny stress fractures which reamin painful or hypersensitive throughout an entire season, thus inhibiting performance ability and quality. Baseball and softball players, therefore, require a glove which maximizes protection against tissue damage and bone contusion.
One such protective device (set forth in U.S. Pat. No. 4,071,913 to Rector) covers the entire hand, including the fingers and wrist, with a leather glove. Additional padding is provided at the fingertips, the palmar surface of the thumb, and the palmar skin from the wrist to the base of the fingers. (Other devices which cover the entire hand include U.S. Pat. Nos. 4,121,824; 4,042,975; 1,797,116 and 3,267,486 to Hirschfield, Elliott, Barden and Madnick, respectively.) Tactilegnosis partially depends, however, on the palmer surface (i.e., the skin on the inner side of the hand), and on the particular sensitivity of the palmar fingertip skin which is roughly 20 to 30 times as sensitive as skin anywhere else on the body. Because these full protective gloves cover the entire palmer surface, the devices eliminate a significant portion of the "fingertip feel" tactilegnotic ability of the hand.
Another protective device covers, by means of a flexible padded tube with a thumbhole, the palmar and dorsal areas from the wrist to the roots of the finger (U.S. Pat. No. 4,176,407 to Goebel). This device is similar to the fingerless glove which leaves each digit completely exposed (U.S. Pat. No. 425,887 to Kohler). A third device covers a portion of each proximal phalanx ("finger" bone) in addition to covering the metacarpal area of the hand. (U.S. Pat. Nos. 325,968; 3,606,614; 3,501,773; 4,183,100 and 2,465,136 to Rawlings, Dimitroff, Stansberry et al, DeMarco and Troccoli, respectively, illustrate examples of this third device.) All of these devices cushion the metacarpophalangeal joints ("knuckles") and both sides of the metacarpal region, but unduly impede tactilegnosis and the ease and effectiveness of grip. Even though the fingertips are left uncovered, the devices interfere with two additional sensations requisite to tactilegnosis: "dorsal resistance" and "wrap-around grasp," described below.
As a "flat" hand contracts, the dorsal skin stretches and extends approximately one and one-half inches, and the associated tissues extend accordingly. The increasing tightness of the skin results in an awareness of increasing skin resistance as the hand tightens into a fist or grasps an object or surface. Ordinarily, this "dorsal resistance" is most noticeable at the dorsal surface of the proximal interphalangeal joints (the innermost joints of the fingers) due to the extreme angular rotation which occurs between the proximal and middle phalanges during hand contraction. Another sensation, that of "palmar compression," results from compression of the palmar tissues during flexion and occurs simultaneously with dorsal resistance. As does the sensation of dorsal resistance, the sensation of palmar compression increases proportionately to the degree of contraction in the hand. In the normal operation of the hand, such as quick catching and throwing during baseball, therefore, dorsal resistance remains proportional to palmar compression. This dual and balanced sensory awareness is crucial in the precise execution of the sensitive hand movement required during sports and other activities.
The second sensation, experienced during flexion, relates to the configurational folding of the palmar tissues as the hand contracts. As the sensitive palmar skin folds (i.e., as the hands contract about a baseball bat) the skin assumes a padded and curved formation. Continuity of this curve is of particular importance between the metacarpals ("palm" bones) and the middle phalanx ("finger" bone) of each digit; it is in this area that the hand curves almost 180.degree. to effect secure grip without overworking the sensitive fingertips. (The thumb has a proximal phalanx which can also rotate a full 180.degree.. Note that the proximal phalanx of the thumb has an approximate mechanical range equivalent to that of the middle phalanx of each finger, and that the proximal phalanx of the thumb can function as the mechanical equivalent of the middle phalanx even though the thumb has two phalanges instead of three.) As the hand contracts, and as the middle phalanges orient to a position parallel with the metacarpals, the folded configuration of the palmar tissues compensates for the sharp angles of the joints and results in the characteristic palmar curve. The phenomenon of curvature may be most easily observed at the base of each finger of the palmer side: the fingers appear to bend there, even though the bones (the proximal phalanges) do not. The palmar curve permits "wrap-around grasp," the ability of the metacarpals and the phalanges to curve around, grip and sense any given surface.
Artificial padding, such as that of the two devices described above, disrupts wrap-around grasp by padding only a portion of the curve; in particular, the devices pad only a portion of the proximal phalanx. Because the proximal phalanx is an entirelyrigid bone and cannot bend to compensate, any partial padding along its palmar surface leaves a space between the object grasped and the uncovered portion of the phalanx, resulting in abnormal palmar sensations and physically insecure grip.
The two described devices also impede normal awareness of dorsal resistance, and do so in two ways. First, they pad the proximal palmar surface, resulting in an increase in the sensation of palmar compression without the normal proportional increase in dorsal resistance at the proximal interphalangeal joints. The imbalanced sensations thus disrupt and impair normal tactilegnosis. Second, the snug partial gloves restrain the skin which lies beneath them, thus requiring abnormal compensatory stretching in the skin at the distal edge of the glove. (Characterized differently, the gloves cause dorsal resistance themselves, and apply it in an abnormal location.) As a result, the tubular protective device described above produces maximum sensation of resistance at the metacarpophalangeal joints ("knuckles"), and the short-fingered glove causes maximum resistance along the proximal phalangeal shafts. Neither device, therefore, preserves the natural compression-balanced sensation of resistance on the proximal interphalangeal joints. Accordingly, neither device permits the normal sensation of dorsal resistance necessary for sensitive and accurate contraction of the hand.
One final difficulty persists throughout most or all of the partial-glove devices: a snug glove covering, exposing all or most of each finger, is difficult to remove. (U.S. Pat. No. 360,135 to Blomstrom sets forth a short-fingered glove with loose extension "tabs" on one, two or three of the digits, but these tabs cannot facilitate glove removal over the remaining two finters.) Such a glove, tight by design, additionally adherent as a result of the natural perspiration of the hand, and without fingertips to pinch and pull, usually must be removed by grasping the wrist portion and inverting the glove over the hand and fingers. The inversion-removal method significantly shortens the life of the glove by subjecting it to stretching both during removal and during the reverse-inversion necessary before the next wearing. (This stretching is often severe, due to the impatience of the inconvenienced wearer.)